Floating Caisson Design · Floating Caisson Design . Concrete Caisson • A standard caisson will...

Floating Caisson Design

Concrete Caisson • A standard caisson will be generally premade, transported by water, and

immersed until it rests on the river or sea bed. The standard type of caisson has a bottom plate, side and head walls allowing it to float. This caisson will be part of a breakwater structure.

Caisson stages Standard caissons are generally prefabricated at a construction dock. When ready, the dock is overflown and the caisson can be transported by water to the actual site using its own buoyancy. It is then sunk under the sea and filled in order to sit it in place.

The Floating stage will be studied. The main loads are the hydrostatic pressures on external walls.

The governing load situation with respect to the design of external concrete elements (walls and floor) occurs during the floating phase. A considerable water load is acting on the outside of the caisson walls, but it is not balanced by a counter load in the inside. Only a small quantity of water is present.

Caisson Geometry The geometry is simple.

Caisson Mesh C35/45 concrete is used. For the floating stage a lower strength concrete will be

considered (C20/25).

Structural elements for bottom slab, external and inner walls are defined. Edge size is 0.25 m.

It is important to check Element axes

orientation of as End Results

are referred to these local axes.

Caisson Loading

External hydrostatic pressures are applied on the walls. Internal pressures are also

considered in order to include the effect of water that might pour during transport.

Self weight and uplift pressure (on slab) are included as well.

Caisson Results

The flotation condition is simulated using springs